Groups representing people who are blind or have low vision advocate for speech indications instead of percussive tones to increase their safety in crossing roadways. However, the Manual on Uniform Traffic Control Devices (MUTCD) mandates that Accessible Pedestrian Signal (APS) revert to the 1-second locator tone during the change interval. 

The previous research identified that more continuous audible countdowns may auditorily mask the sounds of vehicles about to cross the pedestrian path. Additionally, it was found that continuous acoustic information provided by audible countdowns may be more likely to draw cognitive attention away from attending to vehicle sounds, and processing of audible countdowns may be more cognitively demanding, thus decreasing the safety of pedestrians who are blind. This necessitates comprehensive research to address the following two questions from the groups representing people who are blind or have low vision:

• Should the default walk indication be a speech message rather than a percussive tone?
• Should audible countdown information be permitted or required during the pedestrian change interval?

The objective of this research is to use human factors research to investigate the safety and effectiveness of different audible indications and to identify potential revised language for consideration by the National Committee on Unified Traffic Control Devices (NCUTCD).